1916-17.] Observations on the Blood in Gas Poisoning. 
323 
and it may be taken that a count in which the percentage of lymphocytes 
approaches that of the polymorpho-nuclear leucocytes indicates that the 
patient is still suffering from the effects of gassing, provided always 
that there is no other complicating disease present which might produce 
a similar change. A slight relative lymphocytosis is not an uncommon 
finding, and particularly in men from overseas, so that no great reliance 
can be placed upon the sign unless it is marked, i.e. unless the percentage 
of lymphocytes approaches closely that of the polymorpho-nuclear cells. 
3. The cell which is increased is the ordinary small lymphocyte of the 
blood. There may be, in some cases, a diminution in the number of 
polymorpho-nuclear leucocytes which will, of course, accentuate the sign, 
but the increase of lymphocytes is an absolute one. Moreover, it appears 
in cases with a high leucocyte count. 
4. The change is one which develops early, probably within a month of 
the gassing, and continues for a long time, in cases with persistent 
symptoms for at least eighteen months. 
5. The change appears to be independent of the kind of gas, and it is 
shown by patients exhibiting many varieties of symptoms. 
6. It is not clear what the change is due to, but from analogy with 
other conditions exhibiting a lymphocytosis it is probable that chronic 
inflammatory change in respiratory and gastric mucous membranes is at 
least a factor. 
In conclusion, we should like to thank our colleagues in No. 2 Scottish 
General Hospital for their co-operation, notably Captain Glen, who has 
taken a great deal of trouble in looking out cases ; also Miss MacLean, M.D., 
and Mr Malcolm Smith, who carried out many of the differential counts. 
Dr Graham Brown and Miss MacNeil, M.B., supplied us with a number of 
cases from Seafield War Hospital, Leith; and Major Wallace, C.M.G., Red 
Cross Commissioner, gave us access to a number of others. 
LITERATURE. 
Black, Glenn y and Me Nee, British Medical Journal, 1915, ii, 165. 
Hill (Leonard), ibid., 1915, ii, 891. 
Hurst, Medical Diseases of the War, London, 1917; Edward Arnold. 
Schafer, British Medical Journal, 1915, ii, 245. 
Broadbent, ibid., 24 7. 
Miller and Rainy, Lancet, 1917, i, 19. 
( Issued separately October 12, 1917.) 
